JP2003227492A - Vortex pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vortex pump which realizes a downward sloping flow rate/head characteristics, reduces necessary power of an electric motor, and miniaturizes the motor without affecting non-blocking capability. <P>SOLUTION: The vortex pump widely forms a gap between an end at the anti-main plate 12 of the vane 13 of the open type impeller 5 and a suction side wall of a casing 1 facing each other at their ends. The casing 1 has a vortex chamber 7 gradually expanding in axial direction, a drain part forming the start point of the vortex chamber 7 and a diffuser part leading pressure water from the vortex chamber 7 to a delivery port 11 and forms the cross section area of the delivery port 11 to be the smallest in the passages from the diffuser port to the delivery port 11. The casing 1 has a delivery member 14 having a bent part C from the diffuser part to the delivery port 11 and the delivery port 11 opens toward axial direction. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vortex pump having a wide space between a pump casing and an impeller, which allows large foreign matter to pass therethrough and is excellent in non-blocking property. In particular, the vortex pump having improved pump performance. It is about.

[0002]

2. Description of the Related Art FIG. 1 is a diagram showing a structural example of a conventional vortex pump (disclosed as a conventional example in Japanese Patent Publication No. 62-34952). In FIG. 1, 101 is a pump casing, and a motor 103 is mounted on the pump casing 101 via an intermediate casing 102. An impeller 105 is attached to the tip of the motor shaft 104, and is rotationally driven by the motor 103. The impeller 105 includes a main plate 112 and a plurality of blades 11
It consists of three and three. The casing 101 includes an impeller chamber 106, a spiral chamber 107, and legs 108. The spiral chamber 107 has a suction port 110 on one side on the central shaft 109 and a discharge port 1 on the outer periphery.
11, and communicates with the impeller chamber 106 on the side opposite to the suction port 110. From the diameter Ds of the suction port 110, a substantially uniform passage diameter Dd is ensured in all passages in the pump.

In the sewage / dirt pump, the foreign matter passage rate, which is the ratio of the foreign matter passage diameter, which means the size of the fluid passage in the pump, is used as an index showing the non-blocking property. Then, 100% foreign matter passing rate
It is intended for one. A foreign matter passage rate of 100% is excellent in non-blocking property, but it is often inferior in pump performance. In an actual sewage and waste vortex pump, a foreign matter passage rate of about 70% is non-blocking property. It is widely used as a product with well-balanced pump performance.

FIG. 2 is a diagram showing a structural example of a vortex pump having a foreign matter passage rate of 100% (Japanese Patent Laid-Open No. 2000-240584).
Disclosed in Japanese patent publication). In the figure, the parts denoted by the same reference numerals as those in FIG. 1 indicate the same parts, and therefore the description thereof will be omitted. The present vortex pump has an impeller shape in order to improve the performance of the pump, that is, to maintain a certain passing diameter, and to exhibit higher lift performance with the same outer diameter of the impeller 105. In this example, the foreign matter passage diameter determined by the passage between the casing 101 and the blade 113 is set to be smaller than that in the case of FIG.
By devising the shape of, the pump performance is improved.

In the design of pumps using conventional volute pumps including vortex pumps, the drainage area of the volute chamber 107 is a large design factor, and the design of the impeller 105 is optimized and It was important to have an appropriate area and shape. On the other hand, the vortex pump is required to secure non-blocking property as a basic design requirement, and the drainage area and shape should be such that a foreign matter passage diameter as a waste pump is secured and foreign matter is not easily entangled in the drainage section. However, there is a problem in that the drainer cannot be freely determined from the viewpoint of improving the performance of the pump.

From the above-mentioned restrictions on the design of the vortex pump as a sewage / dirt pump, that is, the wide drainage area through which foreign matter easily passes and the shape of an obtuse drainage which makes it difficult for foreign matter to entangle, the performance of the vortex pump is That is, the flow rate-head (Q-H) characteristics tended to have a substantially flat characteristic (the decrease in the head is relatively small even if the flow rate increases) as shown in FIG. In designing an actual vortex pump, not only the above-mentioned flat flow rate-lifting characteristic, but also a characteristic in which a relatively high lift is secured and the flow rate is narrowed down may be required. It was difficult to realize the pump.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and can realize a downward-sloping flow rate-head characteristic without affecting the non-blocking property, and the required power of the electric motor can be reduced. An object of the present invention is to provide a vortex pump that can be reduced in size and can be downsized in an electric motor.

[0008]

In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that an end portion of the open type impeller blade on the side opposite to the main plate and a suction side wall surface of the pump casing facing the end portion are opposed to each other. In a vortex pump with a wide gap, the pump casing has a vortex chamber that gradually expands in the radial direction.
It has a water draining part that forms the starting point of the vortex chamber and a diffuser part that guides pressure water from the vortex chamber to the pump discharge port, and the cross-sectional area of the discharge port is formed to be the smallest between the passages from the diffuser part to the discharge port. It is characterized by

By forming the cross-sectional area of the discharge port as small as possible between the diffuser portion and the discharge port as described above, it is possible to realize the flow rate-head characteristic of the pump which shows a downward-sloping tendency due to the throttling effect of the discharge port. . This means that the flow rate is limited after a certain head is secured, so the required power of the electric motor that drives the pump is reduced, and the electric motor can be downsized. In addition, the drainage part of the swirl chamber of the pump casing, which tends to cause foreign matter blockage, can secure the passage diameter and shape required for a sewage / dirt pump, so the flow-height characteristics tend to descend to the right without affecting non-blocking. Can be realized.

According to a second aspect of the present invention, in the vortex pump according to the first aspect, the casing has a bent portion between the diffuser portion and the discharge port, and the discharge port is opened in the axial direction. It is characterized by

As described above, since there is a curved portion between the diffuser portion and the discharge port, and the discharge port is opened in the axial direction, the cross-sectional area of the discharge port is a passage from the diffuser portion to the discharge port. The resistance of the bent portion is added to the resistance due to the smallest formation between the two, and the tendency of the flow rate-head characteristic to decrease to the right is further promoted, and the motor can be downsized.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 4 and 5 are views showing an example of the structure of the vortex pump according to the present invention, FIG. 4 is a view showing the entire structure of the vortex pump, FIG. 5 (a) is a plan view of the pump casing, and FIG. 5 (b) is It is sectional drawing of a pump principal part. As shown in the figure, the pump portion P and the electric motor portion M are integrally formed, and the impeller 5 is attached to the tip of the electric motor shaft 4 of the electric motor portion M. The impeller 5 includes a main plate 12 and a plurality of blades 13, and the impeller 5 has a discharge port 11
It is watertightly covered by a casing 1 having a suction port 10.

The rotation of the electric motor shaft 4 draws in sewage from the suction port 10, passes it through the side flow passage, and discharges it from the discharge port 11 which opens upward in the axial direction. Outlet 1 of casing 1
As will be described later, a narrowed portion is formed in 1 and has a smaller diameter than the other portions, and has a smaller diameter than the diameter of the discharge pipe 30. Further, the casing 1 is provided with a leg portion 8 composed of a plurality of legs 8a for making the pump self-supporting.

Between the pump portion P and the electric motor portion M, a shaft seal mechanism is provided by a mechanical seal 15 so that the pumped liquid in the pump portion P does not leak to the electric motor portion M side. Oil (not shown) is sealed in a mechanical seal chamber 18 formed by the load bracket 16 and the intermediate casing 17 of the electric motor section M, which lubricates and cools the sliding surface of the mechanical seal 15. .

Since the electric motor section M is used underwater, it is airtightly constructed by an O-ring or the like, and electric power is supplied through the underwater cable 19. A handle 20 for raising or lowering the pump is provided above the electric motor unit M.

The casing 1 is composed of an impeller chamber 6, a spiral chamber 7 and a leg portion 8. The casing 1 has a suction port 10 on one side of the central axis 9 of the spiral chamber 7, and a blade on the side opposite to the suction port 10. It communicates with the passenger compartment 6. The discharge member 14 that connects the swirl chamber 7 and the discharge port 11 includes a drain portion (A portion in FIG. 5) of the swirl chamber 7, a diffuser portion (B portion in FIG. 5), and a bent portion (C portion in FIG. 5). , And the narrowed portion of the discharge port 11 (portion D in FIG. 5). Based on the requirements of a vortex pump as a sewage / dirt pump, the water draining portion of the swirl chamber 7 has a cross-sectional area through which foreign matter can easily pass, and has a water draining portion shape with an obtuse angle that is difficult to get entangled.

Since it is inevitable that the shape of the draining portion as it is will have a flat flow rate-lifting (Q-H) characteristic as shown in FIG. 3, the throttle portion (portion D) is formed again at the discharge port 11. Then, in addition to the draining part (A part) of the swirl chamber 7,
The flow rate of the pump-
We try to change the lift characteristic from a flat one to one that has a relatively large downward sloping tendency.

As shown in FIGS. 5A and 5B, the casing 1 has a bent portion (C portion) between the diffuser portion (B portion) and the discharge port 11, and the discharge port 11 is axially upward. With the opening, the resistance of the bent portion and the resistance of the throttle portion (D portion) formed in the discharge port 11 are added to the casing 1, and the flow rate-head characteristic of the pump is a right-down characteristic. At this time, the narrowed portion of the discharge port 11 has a minimum diameter of 35 mm or more in order to secure a minimum passage diameter as a sewage / dirt pump. Since an appropriate diameter for the discharge pipe 30 of the pump is selected for the flow rate, the discharge pipe 30
And the diameter of the discharge port 11 are set to different sizes.

FIG. 6 is a diagram showing the pump characteristics of the vortex pump according to the present invention and the conventional vortex pump. The horizontal axis shows the flow rate Q, the vertical axis shows the head H, the pump efficiency η, and the shaft power D. The solid line indicates the present invention, and the dotted line indicates the conventional example. In FIG. 6, a is the flow rate-head (QH) characteristic of the present invention,
b is the conventional flow rate-head (Q-H) characteristic, c is the pump efficiency of the present invention, d is the conventional pump efficiency, e is the shaft power of the present invention, f is the conventional shaft power, and g is the electric motor of the present invention. Rating, h shows the conventional motor rating. As shown in the figure, the vortex pump according to the present invention has a flow rate-head (Q-H) characteristic that shows a downward-sloping tendency as compared with the conventional vortex pump, and the motor rating and the shaft power become smaller. Therefore, in the vortex pump according to the present invention, the flow rate-head (Q-H) characteristic can realize a downward-sloping tendency, and the downsizing of the electric motor and the manufacturing cost can be realized.

[0020]

As described above, according to the invention described in each claim, the following excellent effects can be expected.

According to the first aspect of the present invention, the cross-sectional area of the discharge port is formed to be the smallest between the passages from the diffuser portion to the discharge port. Flow rate-head characteristics can be realized. This means that the flow rate is limited after a certain head is secured, so the required power of the electric motor that drives the pump is reduced, and the electric motor can be downsized. In addition, the drainage part of the swirl chamber of the pump casing, which tends to cause foreign matter blockage, can secure the passage diameter and shape required for a sewage / dirt pump, so the flow-height characteristics tend to decrease to the right without affecting the non-blocking. Can be realized.

According to the second aspect of the present invention, since there is a curved portion between the diffuser portion and the discharge port, and the discharge port is opened in the axial direction, the cross-sectional area of the discharge port can be changed. The resistance of the bent portion is added to the resistance due to the smallest formation between the passage from the portion to the discharge port, and the tendency of the flow rate-head characteristic to decrease to the right is further promoted, so that the electric motor can be downsized.

[Brief description of drawings]

FIG. 1 is a diagram showing a structural example of a conventional vortex pump.

FIG. 2 is a diagram showing a structural example of a conventional vortex pump.

3 is a flow rate of the vortex pump having the structure shown in FIG.
It is a figure which shows a lift characteristic and a pump efficiency characteristic.

FIG. 4 is a diagram showing an overall structure of a vortex pump according to the present invention.

5 (a) is a plan view of a pump casing of a vortex pump according to the present invention, and FIG. 5 (b) is a cross-sectional view of a main part of the pump.

FIG. 6 is a diagram showing a comparative example of pump characteristics of the present invention and a conventional vortex pump.

[Explanation of symbols]

1 casing 4 motor shaft 5 impeller 6 Impeller room 7 Whirlpool 8 legs 9 central axis 10 Suction port 11 outlet 12 Main plate 13 feathers 14 Discharge member 15 Mechanical seal 16 load bracket 17 Intermediate casing 18 Mechanical seal room 19 underwater cable 20 handle 30 discharge pipe

Claims (2)

[Claims] 1. A vortex pump having a wide gap between an end of the open type impeller blade on the side opposite to the main plate and a suction side wall surface of the pump casing facing the end, wherein the pump casing gradually expands in a radial direction. Swirl chamber,
It has a water draining part that forms the starting point of the vortex chamber and a diffuser part that guides pressure water from the vortex chamber to the pump discharge port, and the cross-sectional area of the discharge port is formed to be the smallest between the passages from the diffuser part to the discharge port. A vortex pump characterized by that. 2. The vortex pump according to claim 1, wherein the casing has a bent portion between the diffuser portion and the discharge port, and the discharge port is opened in the axial direction. Vortex pump.